Finding the Fourth Proportional to 3,945.72, 5,911.20 and 3,540

Step by Step Solution

1. Step 1: Write the proportion equation
   3,945.72 : 5,911.20 = 3,540 : x
2. Step 2: Convert to fraction form
   3,945.72/5,911.20 = 3,540/x
3. Step 3: Cross multiply
   3,945.72x = 5,911.20 × 3,540
4. Step 4: Simplify right side
   3,945.72x = 20,925,648
5. Step 5: Solve for x
   x = 20,925,648/3,945.72
6. Step 6: Final answer
   x = 5,303.38